windows socket select

如题：

/*参考博客：http://blog.csdn.net/zjsiva/article/details/5895087*/#include "stdafx.h"#include <windows.h>#include <stdlib.h>#include <WINSOCK2.H>#pragma comment(lib,"ws2_32.lib")int _tmain(int argc, _TCHAR* argv[]){WSADATA WSAData;SOCKET ServerSocket;struct sockaddr_in ServerAddr;/*MAKEWORD定义是这样的：#define MAKEWORD(a, b) \ ((WORD) (((BYTE) (a)) | ((WORD) ((BYTE) (b))) << 8)) WSAStartup函数的第一个参数指明程序请求使用的Socket版本，其中高位字节指明副版本、低位字节指明主版本；操作系统利用第二个参数返回请求的Socket的版本信息。*/if(WSAStartup(MAKEWORD(2,2),&WSAData)!=0){printf("Init windows socket failed::%d\n",GetLastError());return 1;}ServerSocket=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);if(ServerSocket==INVALID_SOCKET){printf("Create socket failed::%d\n",GetLastError());WSACleanup();return 1;}ServerAddr.sin_family=AF_INET;ServerAddr.sin_addr.S_un.S_addr=htonl(INADDR_ANY);ServerAddr.sin_port=htons(10086);int iResult;bool bReuseAddr=true;/* bReuseAddr=0x01 *//*第二个参数是被设置的级别，如果想要在套接字级别上设置选项，就必须把参数设置为SOL_SOCKETSO_REUSEADDR提供如下四个功能：SO_REUSEADDR允许启动一个监听服务器并捆绑其众所周知端口，即使以前建立的将此端口用做他们的本地端口的连接仍存在。这通常是重启监听服务器时出现，若不设置此选项，则bind时将出错。SO_REUSEADDR允许在同一端口上启动同一服务器的多个实例，只要每个实例捆绑一个不同的本地IP地址即可。对于TCP，我们根本不可能启动捆绑相同IP地址和相同端口号的多个服务器。SO_REUSEADDR允许单个进程捆绑同一端口到多个套接口上，只要每个捆绑指定不同的本地IP地址即可。这一般不用于TCP服务器。SO_REUSEADDR允许完全重复的捆绑：当一个IP地址和端口绑定到某个套接口上时，还允许此IP地址和端口捆绑到另一个套接口上。一般来说，这个特性仅在支持多播的系统上才有，而且只对UDP套接口而言（TCP不支持多播。*/iResult=setsockopt(ServerSocket,SOL_SOCKET,SO_REUSEADDR,(char *)&bReuseAddr,sizeof(bReuseAddr));if(SOCKET_ERROR==iResult){printf("Failed to set reuseaddr socket::%d\n",GetLastError());return 1;}if(bind(ServerSocket,(struct  sockaddr *)&ServerAddr,sizeof(ServerAddr))!=0){printf("Bind socket failed::%d\n",GetLastError());return 1;}if(0!=listen(ServerSocket,5)){printf("Failed to listen client::%d\n",GetLastError());WSACleanup();return 1;}/*typedef struct fd_set {u_int fd_count;                 // how many are SET? SOCKET  fd_array[FD_SETSIZE];   // an array of SOCKETs } fd_set;*/fd_set fd;//将套接字集合清空FD_ZERO(&fd);FD_SET(ServerSocket,&fd);printf("Start server...\n");u_int i;SOCKET acceptSocket;sockaddr_in acceptSockAddr;int iAcceptLen=sizeof(acceptSockAddr);char szDataBuffer[1024];int iRecvSize;sockaddr_in tempSockAddr;int iTempLen;while(1){fd_set fd_pre=fd;/*int select (int nfds,                           fd_set FAR * readfds,               fd_set FAR * writefds,              fd_set FAR * exceptfds,             const struct timeval FAR * timeout  );*/iResult=select(0,&fd_pre,NULL,NULL,NULL);if(0<=iResult){for(i=0;i<fd.fd_count;i++){if(FD_ISSET(fd.fd_array[i],&fd_pre)){//如果socket是服务器，则接收连接if(fd.fd_array[i]==ServerSocket){memset(&acceptSockAddr,0,sizeof(acceptSockAddr));//这里是接受连接acceptSocket=accept(ServerSocket,(sockaddr *)&acceptSockAddr,&iAcceptLen);if(acceptSocket!=INVALID_SOCKET){FD_SET(acceptSocket,&fd);printf("%s:%d has connected to server\n",inet_ntoa(acceptSockAddr.sin_addr),ntohs(acceptSockAddr.sin_port));}}else//非服务器，接受数据(因为fd是读数据集){memset(szDataBuffer,0,sizeof(szDataBuffer));iRecvSize=recv(fd.fd_array[i],szDataBuffer,1024,0);memset(&tempSockAddr,0,sizeof(tempSockAddr));iTempLen=sizeof(tempSockAddr);/*The getpeername function retrieves the name of the peer connected to the socket s and stores it in the aSOCKADDR structure identified by name.*/getpeername(fd.fd_array[i],(sockaddr *)&tempSockAddr,&iTempLen);if(iRecvSize==SOCKET_ERROR){closesocket(fd.fd_array[i]);FD_CLR(fd.fd_array[i],&fd);i--;printf("Failed to recv data, %s:%d errorcode:%d.\n",inet_ntoa(tempSockAddr.sin_addr),ntohs(tempSockAddr.sin_port),WSAGetLastError());continue;}if(iRecvSize==0){printf("%s:%d has closed!\n",inet_ntoa(tempSockAddr.sin_addr),ntohs(tempSockAddr.sin_port));closesocket(fd.fd_array[i]);FD_CLR(fd.fd_array[i],&fd);i--;}if(iRecvSize>0){printf("recv %s:%d data:%s\n",inet_ntoa(tempSockAddr.sin_addr),ntohs(tempSockAddr.sin_port),szDataBuffer);}}}}}}WSACleanup();return 0;}